Prediction of wrinkling and springback in sheet metal forming

The finite element simulation is currently a powerful tool to optimize forming processes in order to produce defect-free products. Wrinkling and springback are main geometrical defects arising in sheet metal forming. Nevertheless, the prediction of such defects requires accurate numerical models. This study presents the experimental and numerical analysis of a rail with high tendency to develop both wrinkling (top surface of geometry) and springback (flange). The punch force evolution and the final geometry of the rail, evaluated in four different cross-sections, are the main variables analysed. Globally, the numerical results are in good agreement with the experimental measurements. However, the shape of the wrinkle is significantly influenced by the symmetry conditions considered in the model (1/4 of the blank). In fact, considering the full model of the blank, the numerical results are in better agreement with the experimental ones. On the other hand, the computational cost of the numerical simulation considering the full blank is approximately 12 times higher than using 1/4 of the blank.